Association between tea consumption and colorectal cancer: a systematic review and meta-analysis of a population-based study

Purpose A meta-analysis study was performed to systematically assess the association between tea consumption and CRC risk. Methods Cochrane Library, Embase, PubMed, and Web of Science were retrieved to collect articles in English since 24 July 2023. Databases were searched and evaluated by two reviewers independently.We screened the literature based on inclusion and exclusion criteria. After determining the random effect model or fixed utility model based on a heterogeneity test, odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Results We included fourteen articles in this meta-analysis. We analyzed the data using a random effect model to explore the association between tea consumption and CRC because of apparent heterogeneity (P<0.001, I-2=99.5%). The combined results of all tests showed that there is no statistically significant association between tea consumption and CRC risk (OR=0.756, 95%CI=0.470-1.215, P=0.247). Subsequently, subgroup analysis and sensitivity analysis were performed. Excluding any single study, the overall results ranged from 0.73 (95%CI=0.44-1.20) to 0.86 (95%CI=0.53-1.40). It was determined that there was no significant publication bias between tea consumption and CRC risk (P=0.064) by Egger's tests. Conclusions The results indicated that tea consumption may not be significantly associated with the development of CRC. Implications of key findings Tea reduces colon cancer risk by 24%, but the estimate is uncertain. The actual effect on risk can range from a reduction of 51% to an increase of 18%, but regional and population differences may cause differences.